Add fuzzer for Unbound's parse_packet. (#2149)

* Add fuzzer for Unbound's parse_packet.

projects/unbound/Dockerfile

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+# Copyright 2019 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+################################################################################
+FROM gcr.io/oss-fuzz-base/base-builder
+MAINTAINER jsha@letsencrypt.org
+RUN apt-get update
+RUN apt-get install -y make libtool libssl-dev libexpat-dev wget
+RUN git clone --depth=1 https://github.com/NLnetLabs/unbound unbound
+WORKDIR unbound
+COPY parse_packet_fuzzer.c .
+COPY build.sh $SRC/

projects/unbound/build.sh

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+#!/bin/bash -eux
+# Copyright 2019 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+################################################################################
+# util/storage/lookup3.c has some code that triggers the address sanitizer, but
+# according to a comment is OK. -DVALGRIND turns on an alternate version of that
+# code.
+CFLAGS="${CFLAGS} -DVALGRIND=1"
+./configure
+make -j6 all
+
+$CC $CFLAGS -I. -DSRCDIR=. -c -o parse_packet_fuzzer.o parse_packet_fuzzer.c
+
+$CXX $CXXFLAGS -std=c++11 \
+  -lFuzzingEngine \
+  -lssl -lcrypto -pthread \
+  -o $OUT/parse_packet_fuzzer \
+  parse_packet_fuzzer.o \
+  dns.o infra.o rrset.o dname.o \
+  msgencode.o as112.o msgparse.o msgreply.o packed_rrset.o iterator.o \
+  iter_delegpt.o iter_donotq.o iter_fwd.o iter_hints.o iter_priv.o \
+  iter_resptype.o iter_scrub.o iter_utils.o localzone.o mesh.o modstack.o view.o \
+  outbound_list.o alloc.o config_file.o configlexer.o configparser.o \
+  fptr_wlist.o edns.o locks.o log.o mini_event.o module.o net_help.o random.o \
+  rbtree.o regional.o rtt.o dnstree.o lookup3.o lruhash.o slabhash.o \
+  tcp_conn_limit.o timehist.o tube.o winsock_event.o autotrust.o val_anchor.o \
+  validator.o val_kcache.o val_kentry.o val_neg.o val_nsec3.o val_nsec.o \
+  val_secalgo.o val_sigcrypt.o val_utils.o dns64.o cachedb.o redis.o authzone.o \
+  respip.o netevent.o listen_dnsport.o outside_network.o ub_event.o keyraw.o \
+  sbuffer.o wire2str.o parse.o parseutil.o rrdef.o str2wire.o strlcat.o \
+  getentropy_linux.o reallocarray.o libunbound.o \
+  explicit_bzero.o libworker.o context.o \
+  strlcpy.o arc4random.o arc4random_uniform.o arc4_lock.o
+
+wget --directory-prefix $OUT https://github.com/jsha/unbound/raw/fuzzing-corpora/testdata/parse_packet_fuzzer_seed_corpus.zip

projects/unbound/parse_packet_fuzzer.c

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+#include "config.h"
+#include "util/regional.h"
+#include "util/fptr_wlist.h"
+#include "sldns/sbuffer.h"
+
+struct regional * region = NULL;
+
+int LLVMFuzzerTestOneInput(const uint8_t *buf, size_t len)
+{
+	if (!region) {
+		region = regional_create();
+		if (!region) {
+			abort();
+		}
+}
+	sldns_buffer pktbuf;
+	sldns_buffer_init_frm_data(&pktbuf, (void*)buf, len);
+
+	struct msg_parse prs;
+	memset(&prs, 0, sizeof(prs));
+	parse_packet(&pktbuf, &prs, region);
+	return 0;
+}

projects/unbound/project.yaml

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+homepage: "https://nlnetlabs.nl/projects/unbound/about/"
+primary_contact: "wouter@nlnetlabs.nl"